Polyvinyl chloride printing roller



Jan. 2, 1951 J. SPENCER 2,536,323

POLYVINYL CHLORIDE PRINTING ROLLER Filed March 18, 1947 -//Z I M l3 Fv z .3 k j N F271] N h I /Z x :1

INVENTOK 2 u. sPiLncnk ATT Y5 Patented Jan. 2, 1951 POLYVINYL CHLORIDE PRINTING ROLLER James Spencer, Toronto, Ontario, Canada, assiznor to Penna-Flex Industries Limited, Toronto, @ntario, Canada, an incorporated company oi Untarlo Application March ill, ltll'l, dcrlal Noa 335,297

3 Claims. (Us im -43) This invention relates to a material for making printing rollers and plates and a method for making the same.

Hitherto, printing rollers have generally been made from a composition oi alycerine and animal clue which is suitably processed and cast to rive the surface characteristics necessary for the purpose. Various attempts have been made to use synthetic materials for the production oi such rollers but up until the present these have hecn unsucccssiul. The chiei drawbacks to using the animal glue-glyccrinc roller, which is in all other respects highly satisfactory, are that it is water soluble and, therefore, cannot be used with inks which have water as a component and, iurthcr, the glycerine rollers will melt at temperatures above lilo" i and, consequently, are unsuitable for high speed rollers where temperatures are often in excess of this figure. Rollers at this type are further subject to the disadvantage that their dimensions alter under dificrcnt conditions of humidity,

Accordingly, it is the object of the present invention to provide a printing roller which can he used with inirs containing a wide ranse ol materials including water.

it is another object of the invention to provide a printing roller which may be used at tempera tures up to 25il to 300 F. without loss at cmciency.

It is a iurther object of this invention to pro-=- vide a simple process for making such rollers.

Figure 1 is a diagrammatic sectional side view oi a mold suitable for purposes of the invention.

Figure 2 is a partly cut-away perspective view 01 a finished roller.

Figure 3 is a plan view of one of the spacer elements used to position the metal core within the mold shown in Figure l.

Referring now more specifically to the drawings, Figure 1 shows generally the arrangement of the mold which is generally completely housed within a temperature control oven at a temperature slightly in excess of the temperature of the plastic being poured. The mold consists of a hollow cylinder l within which are annular ribs I l which are discontinuous to provide for passage and support of spacer element II which is used to support the metallic roller core It. The cylinder I0 is completely housed within a water jacket l4 provided with inlet l5 and outlet l6 and a gate tube I! communicates with the bottom part I8 01' the cylinder II to introduce the melted plastic thereto. The molding operation is as follows:

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The complete molding apparatus is brought up to a temperature slightly in excess oi the melt in a temperature control oven and the melt is introduced in the funnel it at the and oil the gate tuhe ill. The melt feeds down into the bottom of the mold and gradually iollows it to a point above the upper spacer member i2. This operation is carried out fairly slowly to obviate the inclusion oi air bubbles within the hotly of the plastic. its soon as the mold is full, cooling water is introduced into the water jacket through inlet ill and the mold is cooled rapidly and evenly to room temperature and the completed roller it is removed and trimmed. to size.

Suitable proportions oi ingredients are host illustrated by reference to the following examples:

The alcove composition produces a rubbery substance suitable for high speed rollers and with only a slight amount at tack on the surface.

Example ii Polyvinyl chloride llld Plastlciser 130 Ester sum 5 ldurnt sienna 5 The substance produced by the above proportions oi ingredients is very much the same as that in the above example with the exception that the above composition surface is considerably more tacliy.

Example ill Polyvinyl chloride lilil Dl-octyl phthalate -l 20d Ester gum M l A slightly softer composition with a surface tack suitable for normal printing purposes.

Example IV Polyvinyl chloride Plastlciser 500 Ester gum 3 Burnt sienna 4 A much softer composition with reasonable surface tack suitable for low speed rollers.

A much harder composition with good surface tack ideal for high speed rollers.

Example VI Polyvinyl chloride 100 Plasticiser 400 Ester gum A very soft substance suitable for low speed rollers.

Example VII Plastic 100 Plasticiser 300 Ester gum 100 An extremely tacky soft surface unsuitable for rollers but suitable for special purposes where high tackiness is desirable.

Example VIII Polyvinyl chloride 100 Plasticiser 300 Resin 20 A soft substance with good tack suitable for low speed rollers.

Although an plasticisers which are compatible with the thermo-plastic and the phenolics and resins are suitable, the following have proved particularly suitable for use with vinyl chloride resin: tri-octyl phosphate; di-octyl phthalate; di-ethylene glycol; (ii-ethylene glycol mono-ethyl ether; and di-ethylen'e glycol di-butyl ether. These have been round particularly suitable for use with ester gum as a tackifier but may be used with any resin which is compatible with ntrocellulose or polyvinyl chloride and the above mentioned group of plasticisers. Such resins are those generally found in the ester gum class utilized as varnish or lacquer resins. With regard to compatibility of plasticisers, it is merely necessary to test the resin with a small amount of plasticiser to determine whether or not the two may be used in the same roller.

Accordingly, it will be seen that this invention permits a wide application in the printing roller and plate industry fulfilling the long felt want of providing a roller which will remain emcient at higher temperatures than are encountered in high-speed rollers and which will, in addition, efiiciently print inks which contain a water base. Various modifications and changes may be made in the preparations of the ingredients used depending upon the particular purpose to which a particular roller is to be put. Accordingly, it is not desired that the breadth ofthe invention be limited in any way except as set out in the accompanying claims.

What I claimas my invention is:

l. A printing roller having a core and a fixed r surround on the surface whereof is formed a cylindrical inking surface coaxial to said core, said surround being composed of a homogeneous composition consisting essentially of rubbery plasticised polyvinyl chloride containing from about 1 to about 5% by. weight or compatible ester gum.

2. A printing roller as defined in claim 1, in which the polyvinyl chloride is plasticised with di-octyl phthalate.

3. A printing roller as defined in claim 2, in which the proportion of di-octyl phthalate to polyvinyl chloride is substantially 13:10.

JAMES SPENCER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 830,432 Hennessey Sept. 4, 1906 1,870,661 Vogt Aug. 9, 1932 1,929,453 Semon Oct. 10, 1933 2,028,712 Swan et al Jan. 21, 1936 2,075,106 Fordyce et al. Mar. 30, 1937 OTHER REFERENCES Fritz et al., page 41, India Rubber World, Mar. 1, 1938.

Koroseal Handbook of Tech. Info. pp. 9-12, pub. 1942 by B. F. Goodrich Co.

Koroseal Handbook of Technical Information, pages 5, 14, 15 and 19, pub. 1942 by B. F. Goodrich Co. 

1. A PRINTING ROLLER HAVING A CORE AND A FIXED SURROUND ON THE SURFACE WHEREOF IS FORMED A CYLINDRICAL INKING SURFACE COAXIAL TO SAID CORE, SAID SURROUND BEING COMPOSED OF A HOMOGENEOUS COMPOSITION CONSISTING ESSENTIALLY OF RUBBERY PLASTICISED POLYVINYL CHLORIDE CONTAINING FROM ABOUT 1 TO ABOUT 5* BY WEIGHT OF COMPATIBLE ESTER GUM. 